Autonomous polymer compounding optimization

Abstract

A testing apparatus for obtaining mechanical properties of a polymer composite extruded from a nozzle of a compounding extruder includes a plurality of pairs of roller units that roll the polymer composite along a first direction. Each of the pairs of roller units includes a first roller unit and a second roller unit disposed such that a center of the first roller unit and a center of the second roller unit are separated by a predetermined distance in a second direction that is perpendicular to the first direction. The pairs of roller units are disposed along the first direction such that the predetermined distance of each of the pairs of roller units increases stepwise along the first direction. The pairs of roller units strain a vulnerable portion of the polymer composite in the second direction. The testing apparatus further includes a sensor that measures stress in the vulnerable portion.

What is claimed is: 
     
       1. A testing apparatus for obtaining mechanical properties of a polymer composite extruded from a nozzle of a compounding extruder, the testing apparatus comprising:
 a plurality of pairs of roller units that roll the polymer composite along a first direction, wherein
 each of the pairs of roller units comprises a first roller unit and a second roller unit disposed such that a center of the first roller unit and a center of the second roller unit are separated by a predetermined distance in a second direction that is perpendicular to the first direction, 
 the pairs of roller units are disposed along the first direction such that the predetermined distance of each of the pairs of roller units increases stepwise along the first direction, 
 the polymer composite extruded from the nozzle has a U-shaped profile with a side wall and upper and lower portions surrounding the side wall, wherein the upper and lower portions are thicker than the side wall in a cross-sectional view of the polymer composite, and 
 the pairs of roller units increasingly strain the side wall that is a vulnerable portion of the polymer composite in the second direction as the polymer composite moves through the pairs of roller units in the first direction and the predetermined distance increases stepwise; and 
 
 a sensor that measures stress in the side wall of the polymer composite. 
 
     
     
       2. The testing apparatus according to  claim 1 , wherein a distance between each adjacent pairs among the pairs of roller units is constant along the first direction. 
     
     
       3. The testing apparatus according to  claim 1 , wherein the pairs of roller units are disposed along the first direction such that the predetermined distance of each of the pairs of roller units increases linearly along the first direction. 
     
     
       4. The testing apparatus according to  claim 1 , wherein
 in at least one of the pairs of roller units, the first roller unit comprises a pair of upper rollers and a pair of lower rollers, wherein 
 in the second direction, the second roller unit is disposed between the pair of upper rollers and the pair of lower rollers. 
 
     
     
       5. The testing apparatus according to  claim 4 , wherein
 the pair of upper rollers and the pair of lower rollers of the first roller unit roll a bottom portion of the U-shaped profile, and 
 the second roller unit rolls a top portion of the U-shaped profile. 
 
     
     
       6. The testing apparatus according to  claim 4 , wherein in a third direction perpendicular to the first direction and the second direction, the second roller unit is disposed between the pair of upper rollers and the pair of lower rollers of the first roller unit. 
     
     
       7. The testing apparatus according to  claim 1 , wherein
 the sensor comprises load cells, 
 each of the load cells is disposed on a second roller unit of a respective pair of roller units, and 
 each of the load cells measures the stress in the side wall of the polymer composite by measuring a force applied from the second roller unit of the respective pair of roller units upon rolling the polymer composite. 
 
     
     
       8. The testing apparatus according to  claim 1 , wherein
 the sensor is an optical sensor, 
 the optical sensor comprises a camera that acquires images of the side wall of the polymer composite, and 
 the sensor measures the stress on the side wall of the polymer composite using the acquired images. 
 
     
     
       9. A method for measuring mechanical properties of a polymer composite extruded from a nozzle of a compounding extruder, the method comprising:
 rolling the polymer composite along a first direction using a plurality of pairs of roller units, each of the pairs comprising a first roller unit and a second roller unit, wherein
 a center of the first roller unit and a center of the second roller unit are separated by a predetermined distance in a second direction that is perpendicular to the first direction, and the predetermined distance of each of the pairs of roller units increases stepwise with respect to the first direction, and 
 the polymer composite extruded from the nozzle has a U-shaped profile with a side wall and upper and lower portions surrounding the side wall, wherein the upper and lower portions are thicker than the side wall in a cross-sectional view of the polymer composite; 
 
 increasingly straining the side wall that is a vulnerable portion of the polymer composite in the second direction as the polymer composite moves through the pairs of roller units in the first direction and the predetermined distance increases stepwise; and 
 measuring stress in the side wall using a sensor. 
 
     
     
       10. The method according to  claim 9 , wherein
 at least in one of the pairs of roller units, the first roller unit of the pair of roller units comprises a pair of upper rollers and a pair of lower rollers, 
 in the second direction, the second roller unit is disposed between the pair of upper rollers and the pair of lower rollers of the first roller unit, and 
 the rolling of the polymer composite comprises:
 rolling a bottom portion of the U-shaped profile by the pair of upper rollers and the pair of lower rollers; and 
 rolling a top portion of the U-shaped profile by the second roller unit. 
 
 
     
     
       11. The method according to  claim 9 , wherein the stress in the side wall of the polymer composite is measured by load cells, each of which is disposed on the second roller unit of the respective pairs of roller units. 
     
     
       12. The method according to  claim 9 , wherein the stress in the side wall of the polymer composite is measured by using images of the side wall of the polymer composite acquired by a camera. 
     
     
       13. A non-transitory computer readable medium (CRM) storing instructions for performing operation that causes a testing apparatus to obtain mechanical properties of a polymer composite extruded from a nozzle of a compounding extruder, the operation comprising:
 rolling the polymer composite along a first direction using a plurality of pairs of roller units, each of the pairs comprising a first roller unit and a second roller unit, wherein
 a center of the first roller unit and a center of the second roller unit are separated by a predetermined distance in a second direction that is perpendicular to the first direction, and the predetermined distance of each of the pairs of roller units increases stepwise with respect to the first direction, and 
 the polymer composite extruded from the nozzle has a U-shaped profile including a thin side wall and upper and lower portions surrounding the side wall, wherein the upper and lower portions are thicker than the side wall in a cross-sectional view of the polymer composite; 
 
 increasingly straining the side wall that is a vulnerable portion of the polymer composite in the second direction as the polymer composite moves through the pairs of roller units in the first direction and the predetermined distance increases stepwise; and 
 measuring stress in the side wall using a sensor. 
 
     
     
       14. The CRM according to  claim 13 , wherein
 at least in one of the pairs of roller units, the first roller unit of the pair of roller units comprises a pair of upper rollers and a pair of lower rollers, 
 in the second direction, the second roller unit is disposed between the pair of upper rollers and the pair of lower rollers of the first roller unit, and 
 the rolling of the polymer composite comprises:
 rolling a bottom portion of the U-shaped profile by the pair of upper rollers and the pair of lower rollers; and 
 rolling a top portion of the U-shaped profile by the second roller unit. 
 
 
     
     
       15. The CRM according to  claim 13 , wherein the stress in the side wall of the polymer composite is measured by load cells, each of which is disposed on the second roller unit of the respective pairs of roller units. 
     
     
       16. The CRM according to  claim 13 , wherein the stress in the side wall of the polymer composite is measured by using images of the side wall of the polymer composite acquired by a camera.